Dialing numbers starting with 8

My provider let users test 911 settings by dialing 811 to simulate emergency call. However when I dial 811, pbxes complains that I'm trying to call nonexistent conference number, and doesn't passes the number to the trunk.

Anyone?

This post has been edited 1 time(s), it was last edited by dor on 23.03.2009 at 22:15.